In the field of health care, vacuum systems are required in many circumstances. A vacuum may be required to be applied to a patient for a variety of reasons.
In these cases care must be taken to ensure that the level of vacuum negative pressure is maintained at the level required for a particular treatment. To do this, manual controls, known as vacuum regulators, are provided by which the level of vacuum pressure can be controlled and varied.
Pressure gauges are also provided, either incorporated in or matched with the vacuum regulator, which monitor the level of vacuum pressure.
In the past the mechanical systems in such vacuum regulators for actually varying and controlling the vacuum used simple vent valves and the like. Such valves could be controlled manually usually by a control knob. The pressure gauge was usually a mechanical-type gauge, which consisted of a pressure sensor with a dial and a needle showing the pressure. An operator would glance at the dial and needle from time to time to ensure that the vacuum level remained stable at the desired pressure.
Such known pressure gauge systems have been somewhat primitive.
Usually known vacuum regulators used a simple mechanical-type pressure gauge with a needle-type readout dial showing the pressure. An operator would monitor the gauge reading and might adjust the manual pressure control as desired. This system was somewhat old fashioned for the hospital environment, and was not always practical in emergency situations, for example in a paramedic environment, at an accident scene, or in an ambulance. For example, the needle dial may require to be checked repeatedly, and it was possible for the paramedic to misread the dial. An example of a needle dial-type readout is shown in U.S. Pat. No. 4,915,132 where the needle dial is removably securable to a round post. The dial is sealed against leakage by “O” rings.
Such known systems were also capable of providing for intermittent vacuum pulses to be supplied at intervals as shown, for example, in U.S. Pat. No. 5,599,308. The intermittent control in many cases was difficult to maintain and difficult to regulate as to timing.
U.S. Pat. No. 4,988,336 issued on Jan. 29, 1991, to G S Kohn, discloses a complex vacuum pressure regulator in which the vacuum source is used to drive a rotary air-powered motor which in turn drives an electrical generator, which is part of the regulator. The vacuum control valve is electrically operated and turns the vacuum on and off for intermittent supply of vacuum to the patient. This system is unnecessarily complex in that it incorporates its own electrical generator, and uses that generator to power the electronic on/off switching of the vacuum.
U.S. Pat. No. 5,419,768 issued on May 30, 1995, to J. P. Kayser discloses a vacuum regulator in which the actual vacuum control valve is operated by a solenoid. The solenoid is programmed to open and close the valve automatically for intermittent operation. This system is also complex and would consume a considerable power supply.
There is a need for a vacuum pressure regulator having a more precise pressure readout, preferably one that provides a better visual readout, such as could be provided by a digital numeral LCD display.
Preferably such a system will be independent of mains power (i.e. connected to wiring in a building), and will be a system that is solid state operated with battery power, for most applications, thus permitting it to be used anywhere in a facility or in the field if needed.
Preferably the vacuum pressure display will be incorporated in the body of a manual vacuum pressure regulator so that the digital vacuum pressure display is provided in a single compact unit.
Preferably there will also be an alarm of some form incorporated in the pressure gauge, which will alert the attendant if there is a loss of vacuum.
Preferably the pressure regulator will be designed to operate on a minimum of power so that it can be powered by a long-life battery, a rechargeable battery, a 12-volt battery, or by solar power if desired. Mains power connections could also be incorporated so as to be available to be used, when required, as an optional alternative supply.
The regulator control will preferably incorporate a potentiometer connected to the logic so that when the control knob is rotated to adjust the pressure, the sampling rate is increased temporarily. This will give an instantaneous readout on the display of the new pressure.